From Kodansha:
Hotaru is a 16-year-old high school first-year who has always been ambivalent about love, preferring instead to have a lively life with her family and friends. So when she sees her schoolmate, Hananoi-kun, sitting in the snow after a messy, public breakup, she thinks nothing of offering to share her umbrella. But when he asks her out in the middle of her classroom the next day, she can't help but feel that her life is about to change in a big way.

Note: Nominated for the Best Shoujo Manga at the 44th Kodansha Manga Awards in 2020, won the same award in 2021.

Official English:INKR Comics, Mangamo, Renta!